Manufacturing a semiconductor device includes a process of forming a thin film on a substrate and a process of cleaning the interior of a process chamber, after forming the thin film, by supplying an etching gas such as a fluorine-containing gas, for example, into the process chamber. By the cleaning process, residual deposits (including the same type of film to that formed on the substrate) deposited in the process chamber when forming the thin film on the substrate are removed.
When the thin film formed on the substrate is, for example, a carbon-containing film containing carbon (C), such thin film shows an enhanced film quality, such as an enhanced resistance to wet etching. In this case, residual deposits deposited in the process chamber also include the carbon-containing film.
The residual deposits including the carbon-containing film, which has a high etching resistance, also show a high resistance to a fluorine-containing gas. Thus, the cleaning efficiency is lowered, and in some cases, the residual deposits are not completely removed during the cleaning process.